Patti Sapone/The Star-LedgerTianle "Heidi" Li of Monroe, left, is arraigned on murder charges Wednesday. Li and her attorney Steve Altman , right, listen to the assistant prosector. She is accused of murdering her estranged husband, Xiaoye Wang, by poisoning him with thallium.

"There were a fair number of calls (to police)," Middlesex County Assistant Prosecutor Nicholas Sewitch said today. "More than five."

Things got so bad that Wang, 39, filed for divorce in July, citing irreconcilable differences. He also sought joint custody of the couple’s 2-year-old son, Isaac.

Li, 40, counter-sued a month later, citing the same reason and adding there was "no hope for reconciliation."

The couple’s 10-year marriage appeared to be over.

But on Jan. 14, the day a hearing would be held to finalize the divorce, Wang admitted himself to the University Medical Center in Princeton with "virus-like" symptoms. He died 12 days later from thallium poisoning, which authorities allege was administered by his wife.

Li remained at the Middlesex County jail in North Brunswick today in lieu of $4.15 million bail, charged with murder and hindering her own apprehension. Her attorney, Steven Altman, said his client denies having anything to do with her husband’s death.

Records indicate Wang moved out of the couple’s home on Stanley Drive home in Monroe sometime in June and into a Jersey City apartment.

Preceding the legal steps to end their marriage were calls to police, starting in April 2009 — about seven months after they had moved to Monroe.

Sewitch said none of the calls resulted in charges because there was never any sign of violence or injury to either Li or Wang. While Sewitch would not comment on the origin of the couple’s disputes, neighbors said they often heard them arguing and witnessed frequent visits by police officers.

Wang worked as a computer software engineer in New York City, while Li is a research chemist at the Lawrenceville offices of Bristol-Myers Squibb, the pharmaceutical giant.

After Wang admitted himself into the hospital, his condition progressively deteriorated until he died Jan. 26, the day after doctors finally determined he was suffering from thallium poisoning. After much searching, an antidote was found but by the time it arrived at the hospital, Wang was near death and nothing could be done to save him.

The divorce hearing, which was postponed due to his illness, had been rescheduled for today.

Thallium is a highly toxic heavy metal that is tasteless and odorless. It was once used in rat poison and insecticides, but was banned for that use in the United States and other counties in the 1980s. It is still used in glass and electronics manufacturing and medicinally in stress tests to help diagnose coronary artery disease.

Sewitch has not said how the thallium was administered, nor whether it was given in several small doses over time or in one dose. All he would confirm was that it was ingested in December or January. He also would not comment on where Li allegedly obtained the thallium, though he did say it would have been available to her at Bristol-Myers, where she’s worked since 2001.